Southeast Idaho has a long history of phosphate mining and processing, and the most visible evidence of that industry is Monsanto’s elemental phosphorous plant just north of Soda Springs. Established in 1952, the plant runs three furnaces that turn phosphate ore into elemental phosphorous, which is used in herbicides, hydraulic fluids, and food prouducts. Waste slag from the furnace is poured in molten red streams onto the slag heaps to the west of the plant; this spectacular sight can be seen from Hooper Spring Park (Heritage Site) just outside of town. Tours of the plant are given by special arrangement.